(19)

(11)

EP 0 486 491 A1

(12)

(43) Date of publication: 27.05.1992 Bulletin 1992/22 (21) Application number: 89912822.0 (22) Date of filing: 26.10.1989

(51) International Patent Classification (IPC):  E02F 9/ 20( . ) E02F 3/ 43( . ) (86) International application number: PCT/US1989/004730 (87) International publication number: WO 1991/002853 (07.03.1991 Gazette 1991/06)

(84) Designated Contracting States: BE DE FR GB IT (30) Priority: 17.08.1989 US 19890394919 (71) Applicant: CATERPILLAR INC. Peoria Illinois 61629-6490 (US)	(72) Inventor: SAHM, William, C. Peoria, IL 61615 (US) (74) Representative: Brunner, Michael John, et al  GILL JENNINGS & EVERY Broadgate House 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)